<!DOCTYPE html>
<html>
<head>
    <style>
        .wrap{
            width: 120px;
        }
        .weap span{
            display:block;
            background: red;
            width: 50px;
            height: 50px;
        }
    </style>
</head>
<body>
    <b>11</b>
    <b>21</b>
    <div class="wrap">
        <span>
            h1
        </span>
    </div>
    <div class="head" style="height:1200px">
        <a href="#button">to bottom</a>
        <a name="top"></a>
    </div>
    <div class="footer">
        <a name="button"></a>
        <a href="#top">to top</a>
    <div>
        <span>&nbsp;</span>
        <span>&gt;</span>
        <span>&lt;</span>
        <span>&amp;</span>
    </div>
    <div> 
        <a href="http://baidu.com" target="_blank">link1</a>
        <a href="mailto:921504191@qq.com" target="_blank">link2</a>
        <a href="htp://f.jd.com" target="_blank">link3</a>
    </div>
</body>
</html>